From page 18.
From page 20
On page 11 the picture of the apparatus shows a pressure gauge on the hydrogen inlet, while it doesn't appear to me to be a pressure control gauge "a constant hydrogen pressure of 1100 psig" is explicit in the documentation and "Calculations, documented in Appendix A". Also there appears to be no cutoff valve to retain some pressure if introduced once and just allowed to drift. Reporting of test condition data shows pressure is altered for different test runs indicating pressure control not shown or described in the documentation.
Again, please, read more and assume less.
I notice that page 4 is missing, which may have had some details on the pressure control. What is "explicit" is that a certain pressure of H2 gas, typical around 1000 psi was introduced at the *beginning*. The measurement of heat gain from this pressure increase was calculated for only one such application of pressure, so it is reasonable to assume there was only one application of pressure. Given this, the pressure in the tubing would be allowed to slowly decrease with time as hydrogen diffused through the tubing. Yes they used diffusion rate calculations as if the pressure was held steady at its initial state but imo that is just for calculation simplification purposes and would err on the conservative side.
If I am wrong and Thermacore's setup was actively maintaining a fixed pressure of hydrogen in the tubing, well then that would represent a pretty major blunder in the energy inventory calculation, something I find unlikely.
Recall what is on Thermacore's letterhead on the handwritten reports: "Thermacore Inc. Heat Transfer Specialists Engineering/Manufacturing